The major problem with HDD DNAS is that it requires a file which is built by SONY DNAS server and then saved on the game partition as loader/bootfile, which then boots the game.
Their boot mechanism uses a file called DNASLOAD.ELF which is a MG encrypted elf loaded by the HDD OSD. This one in turn loads the RSA encrypted bootfile (which came from the DNAS server) decrypts it and launches the title.
To open the RSA file the DNASLOAD will take the PS2 and HDD serial numbers as keys. Thus installed files work nowhere but on the HDD/PS2 they were installed with. This is why people must format the HDD to reinstall the game on a new PS2.
Not passing on DNAS checks won't let you install the game files on the HDD.
So no matter what, you won't be playing it on anything but the original/correct region hardware.
SCPH-10000_GH-001 SCPH-15000_GH-003 SCPH-18000_GH-008 SCPH-30001_GH-005 SCPH-30000_GH-016(V4) SCPH-30001_GH-010(V4)
2xSCPH-10190, 2xSCPH-10350, 2xSCPH-10280
"**** j0 hackers!"
-Sjeep (As seen on TOXIC OS ELF...)